diff --git a/src/ConfigProvider.php b/src/ConfigProvider.php
index ccf0a98..2903333 100644
--- a/src/ConfigProvider.php
+++ b/src/ConfigProvider.php
@@ -37,7 +37,7 @@ public function __invoke()
         foreach ($mineJsonPaths as $jsonPath) {
             if (file_exists($jsonPath->getPath() . '/' . Plugin::INSTALL_LOCK_FILE)) {
                 $info = json_decode(file_get_contents($jsonPath->getRealPath()), true);
-                if (! empty($info['composer']['config'])) {
+                if (! empty($info['composer']['config']) && class_exists($info['composer']['config'])) {
                     $provider = (new ($info['composer']['config']))();
                     $initialConfig = array_merge_recursive($provider, $initialConfig);
                 }